1. Technical Field
The present invention relates to a fluid ejection device.
2. Related Art
There is known a technique for ejecting fluid in a pulse-like manner to perform incision, excision, or the like of a target object. For example, in the medical field, as a surgical instrument for incising or excising a biological tissue, there is proposed a fluid ejection device including a pulsed flow generating unit that ejects fluid in a pulse-like manner, a fluid supplying unit that supplies the fluid to the pulsed flow generating unit, a fluid supply path that connects the fluid supplying unit and the pulsed flow generating unit, and an operation switch that switches ON and OFF of the ejecting (see, for example, JP-A-2010-059939 (Patent Literature 1)).
The fluid ejection device increases a driving voltage for a piezoelectric element in the pulsating-current generating unit stepwise to increase ejecting strength of the fluid stepwise and prevents a target region from being cut too deeply.
However, the ejecting strength of the fluid is also affected by the pressure of the fluid in the fluid supplying unit. When the operation switch is operated, the pressure in the fluid supplying unit is not always appropriate.
For example, when the operation switch is operated in a state in which the pressure of the fluid in the fluid supplying unit is too high, it is likely that strong ejecting not intended by a surgeon is performed.
Therefore, there is a demand for a technique for not performing the ejecting of the fluid when the pressure in the fluid supplying unit is equal to or higher than a predetermined upper limit value determined according to ejecting strength and capable of improving the safety of the fluid ejection device.